E-mail processing in modern data processing systems is typically based on a client/server model. An e-mail client, usually deployed on a user's workstation or personal computer receives user input and generates an e-mail message which is typically transferred to the server (generically referred to as a mail transfer agent (MTA). The MTA then transfers the mail to one or more intermediate MTAs and ultimately to an MTA corresponding to the recipient of the e-mail message (as determined by the e-mail address of the addressee). Transfer of the e-mail message commonly uses the Simple Mail Transfer Protocol (SMTP).
In accordance with these e-mail protocols, if a destination is temporarily unreachable, the ingress MTA queues the mail and will attempt to retransmit the mail periodically. Typically a resend algorithm will attempt to resend mail every four hours for up to one week. If after that time the mail still fails, the retries are suspended and the undeliverable mail deleted.
Commonly, such systems will notify the sender that the mail failed and that retries will be attempted. However, a user may subsequently attempt to send e-mail to the same address. However, there is nothing to alert the user that the address may be problematic. Consequently, there is a need in the art for mechanisms to alert a user to a potential problem with an e-mail addressee.